Availability, defined as the fraction of time a network service is operative, is a key network service parameter. Dedicated protection increases availability but also the cost. Shared protection instead decreases the cost, but also the availability. In this article, we formulate and solve an integer linear programming (ILP) model for the problem of minimizing the backup resources required by a ...

We study the problem of scheduling n non-preemptable jobs on a single machine which is not available for processing during a given time period. The objective is to minimize the sum of the job completion times. The best known approximation algorithm for this NP-hard problem has a relative worst-case error bound of 17.6%. We present a parametric O(n log n)-algorithm H with which better worst-case...

The efficient use of bandwidth for radio communications becomes more and more crucial when developing new information technologies and their applications. The core issues are addressed by the so-called Frequency Assignment Problems (FAP). Our work investigates static FAP, where an attempt is first made to configure a kernel of links. We study the problem based on the concepts and techniques of ...

We consider a single machine scheduling problem in which the processing time of a job is a simple linear increasing function of its starting time and the machine is subject to an availability constraint. We consider the non-resumable case. The objectives are to minimize the makespan and the total completion time. We show that both problems are NP-hard and present pseudo-polynomial time optimal ...

Software testing is one activity for Quality Assurance (SQA). One way to test through Black box cases at design level. Since UML a de-facto language and of the most used now day. Therefore, there need black using behavioral diagrams. Object Constraint Language (OCL) formal write constraints on diagrams as it unambiguous. Although against robustness have been designed OCL expressions but no yet ...

This paper deals with a scheduling problem on a single machine with an availability constraint. The problem is known to be NP-complete and admits several approximation algorithms. In this paper we study the approximation scheme described in He et al. [Y. He, W. Zhong, H. Gu, Improved algorithms for two single machine scheduling problems, Theoretical Computer Science 363 (2006) 257–265]. We prov...

Recently, interest in thorium’s potential use in a nuclear fuel cycle has been renewed. Thorium is more abundant, at least on average, than uranium in the earth’s crust and, therefore, could theoretically extend the use of nuclear energy technology beyond the economic limits of uranium resources. This paper provides an economic assessment of thorium availability by creating cumulative-availabil...

the changing of round and back vowel /u/ to unround and front vowel [i] occurs in lori dialects as well as some other persian dialects. this vowel change includes both unrounding and fronting. this paper aimed at coming up with an inclusive ranking of constraints to explain occurrence and nonoccurrence of this vowel change in various phonological environments in silahkori dialect within optimal...

Low nocturnal temperature (LNT) is a major constraint for protected tomato production in China during winter and spring, which leads to phosphorus (P) deficiency symptoms. The soil P fractions reflect availability. foliar root the adaptation strategies of tomatoes LNT. However, relationship between plant under LNT not well understood. Therefore, we conducted 40-day indoor incubation experiment ...

This paper develops an efficient heuristic to solve the non-homogeneous redundancy allocation problem for multi-state series-parallel systems. Non identical components can be used in parallel to improve the system availability by providing redundancy in subsystems. Multiple component choices are available for each subsystem. The components are binary and chosen from a list of products available...